Study On Visible-light-induced Minisci Reaction Involving Aromatic Aldehydes

With the development of human beings,people’s scientific and technological level and the level of industrialization are constantly improving,while the energy crisis and environmental pollution problems are gradually emerging.Therefore,chemists take the pursuit and development of mild,green,efficient and selective synthetic methods as the goal and direction of the new era.Visible light is a unique and abundant resource in nature.It is easy to obtain and pollution-free.It is a green and renewable energy.In recent years,organic reactions catalyzed by visible light have become a research hotspot in synthetic chemistry,among which organic reactions combining photocatalysis with electrochemistry and photocatalysis with traditional heating chemistry have been developed rapidly in the field of synthesis.Nitrogen-containing heterocycles are an important group of skeleton molecules widely used in agricultural chemistry and pharmaceutical chemistry.The functional reaction of nitrogen-containing heterocyclic compounds was quite extensive,especially the classical Minisci reaction.Using the strategy of visible light catalysis,the Minisci reaction was continuously perfected and developed by a large number of scientists,and the heterogeneous functional groupization of the heterocyclic reaction was realized.This paper took"Minisci reaction of aromatic aldehydes under Visible light excitation"as the theme.The photocatalytic Minisci reaction,using quinoline and aromatic aldehydes as raw materials,was mainly studied in the following two aspects:1.A reduction coupling reaction of quinolines with aromatic aldehydes catalyzed by no transition metal under visible light excitation was developed to realize benzyl functionalization of quinolines.In this method,a series of benzylized quinoline compounds were firstly synthesized from quinoline compounds and aromatic aldehydes,using 4Cz IPN as photocatalyst,Li Br as additive,Tf OH and（Ph O）₂PO₂H as mixed acid.This method has mild reaction and wide applicability.2.A direct coupling reaction between quinolines and aromatic aldehydes without transition metal catalyzed by visible light was developed.A series of hydroxymethylated quinoline compounds were prepared by using diphenylquinoline compounds and aromatic aldehyde as raw materials,4Cz IPN as photocatalyst,Li Br as additive and Tf OH as acid.The target product was obtained without external reducing agent under mild conditions,but the substrate applicability and yield need to be further improved.